Setting up a model of grey envelope and forecasting selenium-rich tea production of Wanyuan in 2011,the reaserch is made according to the statistics about output of tea from 2004 to 2010. By examination,the conclusion is that relative error to model of grey envelope is 1.08%,which inferiors to forecast by GM（1.1）. Model precision qualifies as high requirement , it provides bases for promoting selenium-rich tea of Wanyuan development sustainably and healthily.